To the best of my knowledge they all have a rev limiter, but is it the limiter kicking in of are you having a miss. When the rev limiter kicks in the engine just stops making rpm, sort of feels like a miss as the ignition keeps turning on and off. If the engine itself was missing due to other problem it would probably backfire at some point. I haven't had any issues with my 450i so I haven't done any trouble shooting yet. Has the engine revved above 4 thou in the past? Not sure what your rpm specs are on that machine but it might well be brain box on the ignition. Hopefully someone with first hand knowledge will jump in here and help you out..There is also a help/service number at the factory you can call and mabey get some help there. I belong to "cyclepedia" online and they have a trouble shooting service there along with a full factory service manual. For 55 bucks for a lifetime membership it is well worth it!!
